A citywide manhunt ensued after four Manhattan women were fondled in tony neighborhoods in a 35-day stretch. On April 13, authorities paraded their main suspect past snapping cameras.

He defied the conventional image of a creepy perv. He was young, handsome, well-dressed, affluent, educated, a churchgoer.

A gentleman groper.

That suspect, Karl Vanderwoude, says if the scene seemed implausible — that’s because it was.

“I didn’t do it. I wasn’t even in the vicinity of these incidents,” he told The Post in his first interview since his arrest. “It’s a case of mistaken identity.”

The 26-year-old Bible-study leader’s nightmare began 10 days ago, when he left early from his job as an operations coordinator at a Flatiron District private equity firm because he felt sick. He was in his Park Slope apartment for about an hour when the doorbell rang.

“I thought it was my roommate who had been locked out and forgot his keys, which has happened, so I go to answer the door,” he recalled.

Instead, two NYPD detectives were standing in the threshold.

“They’re like, ‘Are you Karl? May we speak with you?’ ”

Cops flashed a surveillance photo and asked Vanderwoude if he knew the man in it.

“Take a closer look. It looks pretty similar to you,” they pressed.

“I said, ‘It’s not me, I don’t know this person.’

“They ask if I’d like to go down to the station and answer some questions. I didn’t have anything to hide. I was happy to go and help.”

But after they arrived at the Special Victims Unit on 119th Street, a creeping doubt began to sink in.

Police brought Vanderwoude into an interrogation room with a two-way mirror. They showed him more photos and a videotape.

“They took my phone and my keys and my wallet. I was in this room for a while. There’s no outside light and it was hard to gauge how long I was there,” he said. “[One officer] showed me the video again. He said, ‘We believe this is you.’ I said, ‘This is not me,’ and I told him they can check my phone, my MetroCards — just to show that I have nothing to hide.”

They were not persuaded. That night, Vanderwoude waited in a jail cell as police arranged to have him stand in three lineups.

“When [the lineups] began, I was relieved — there’s no way they’re going to say it’s me,” he remembered. “I didn’t look like anyone in there. They all had pretty much dark hair, and some of the guys were clearly 50 pounds heavier than me. They were very different looking.”

Apparently, they didn’t look much like the suspect, either.

Police told Vanderwoude that one woman identified him as the perpetrato, but they didn’t give him the results of the other two lineups.

After about 12 hours in custody, police charged Vanderwoude with two counts of third-degree sexual abuse, two counts of forcible touching and one count of second-degree unlawful surveillance. The top charge is punishable by 1 1/3 to four years in prison.

Despite Vanderwoude’s denials, the mother of one victim told The Post her daughter is certain he was her attacker.

“She said, ‘Mom, I knew it the second I walked in there,’ ” the mother said. “He didn’t just grab her butt, he . . . grabbed her crotch. There was lots of bruising.”

The mom said her daughter’s grandmother lives near her assailant.

“She won’t even visit her grandmother now,” she said. “It’s made her whole world shrink.”

Police said Vanderwoude fondled two of the four women — one on the Upper East Side and one in lower Manhattan near City Hall.

They said a Crimestoppers tip led them to the suspect and that he was identified by two victims.

In the downtown attack, NYPD Special Victims Unit Detective Michael Rama alleges that Vanderwoude grabbed a 22-year-old woman between her legs and attempted to film underneath her skirt with a cellphone camera.

In the other incident, police said he grabbed a 19-year-old woman’s buttocks at Second Avenue and East 67th Street.

The case became an NYPD priority, with Police Commissioner Ray Kelly at a press conference on April 10 displaying a surveillance-video picture of the suspect.

Vanderwoude’s world collapsed two days later.

“It felt like a movie,” he said. “I absolutely never thought I’d be handcuffed in my life. When I saw the photographers and video cameras, I thought, ‘What is going on? What happened?’ ”

Before his arraignment, he cooled his heels in a holding cell for two hours and was then paired with his attorney, Lori Cohen, who had been hired by his mother.

“I was choking up. I lost it. I broke down,” he said. “It was the first [time] that someone was on my side, someone was here to help me.”

The hearing was a blur. When it ended, he and his lawyer walked out — he was released on his own recognizance.

“As we were walking through the hall, there were reporters asking me why I did it, do I have anything to say,” he said. “When I leave the courthouse and see even more cameras and reporters, that was when it really started to sink in — this was everywhere.

“My integrity was on the line . . . My name had been tarnished.”

Vanderwoude’s hopes to restore his name hang on purported new evidence gathered by his employer, MVision Private Equity Advisers. The firm claims it has e-mail records, video footage and co-worker accounts giving him a rock-solid alibi.

Vanderwoude’s new attorneys, Douglas Burns and John Tumelty, said they have turned most of those materials over to the Manhattan District Attorney’s Office.

“We have full confidence that they’ll dismiss the case after reviewing the evidence,” Tumelty said. The DA’s Office and the NYPD declined to comment on the new claims.

Police say the March 30 crime occurred at 7:20 p.m. in a subway station at Centre and Chambers streets.

But MVision co-worker Sally Gibb claimed that Vanderwoude was with her at the time.

She claims in a written statement that they left their office at Madison Avenue and East 26th Street “between approximately 6:45 p.m. and 7:15 p.m.,” then had dinner Fifth Avenue until sometime between “8:15 p.m. and 8:45 p.m.”

After that, she claims, they downed drinks at Underbar at the W Hotel in Union Square until after 11 p.m.

MVision lawyers claim e-mail records and video footage also exonerate Vanderwoude in the Feb. 27 attack, when a man grabbed a woman’s behind at 1:54 p.m. near Second Avenue and East 67th Street.

“Video footage records show that Karl did not leave our premises between 13:33 p.m. and 14:38 p.m. and appeared to accept delivery of certain items brought to the firm’s premises during that time,” said Diane Claire Wilkinson, MVision’s general counsel.

Vanderwoude said he hopes his nightmare soon ends — and that the real groper is caught.